I'm not sure I'm concerned with any early round guys yet. Some mid-round guys though:
Mike Davis, his entire selling point was workhorse RB. He's not that by a longshot. He's a borderline cut, as Patterson is a threat, a bad offense hurts, and frankly, this was easy to see coming, but he went as a top-25 RB in most leagues anyway. Same applies to Gaskin, though more people were against him.
Robby Anderson, seems DJ Moore has clearly pulled away from him, and CMC's return has made it too tough for 2 WR's to have value.
Laviska Shenault, Urban Meyer is greatly out of his depth, and has pigeonholed him into a gadget/slot role.
Mark Andrews, this may be premature, but his big selling point was that he was the #1 pass catcher on his team. Sure seems like Hollywood has taken that from him. He's still a starter for fantasy teams, but I'm not sure he's a top-5 guy going forward.